The subprocess-stdin guard (TUI gateway fd-inheritance protection) flagged
the `permissions grant` call. None of the cua-driver probes/grant read
stdin, so DEVNULL is correct; apply it to the shared `_run` helper and the
grant call.
The card was macOS-only. cua-driver also runs on Windows and Linux, so
fold `cua-driver doctor` (cross-platform binary/health probes) into a
single OS-aware `ready` signal:
- macOS: ready == both TCC grants; keeps the permission rows + grant flow.
- Windows/Linux: no TCC toggles, so ready == driver health, with a
per-OS note (SmartScreen/UIAccess on Windows; X11/XWayland on Linux).
`computer_use_status()` replaces the macOS-only `permissions_status()` and
surfaces `platform`, `ready`, `can_grant`, and the doctor `checks` (non-ok
ones render as warnings). CLI `permissions status`, the REST endpoint, and
the desktop card all key off the one payload. Grant stays macOS-only (400
elsewhere — nothing to grant).
Computer Use already worked through the desktop backend (the cua-driver
toolset enables + installs via Settings -> Skills & Tools), but there was
no in-app way to see or grant the two macOS permissions it needs, so "give
a model my Mac" was tribal knowledge.
The grants attach to cua-driver's OWN TCC identity (com.trycua.driver /
the installed CuaDriver.app), not Hermes -- so no app entitlement is
involved. cua-driver 0.5+ exposes `permissions status/grant`, which we wrap:
- tools/computer_use/permissions.py: thin client over the two subcommands
- hermes computer-use permissions {status,grant}: CLI parity
- GET /api/tools/computer-use/status, POST .../permissions/grant: desktop REST
- ComputerUsePanel: live Accessibility + Screen Recording state with a
Grant button (dialog attributed to CuaDriver), shown in the expanded
Computer Use toolset row. Binary install stays in the existing provider
post-setup runner.
Follow-ups: i18n the card copy; a "Stop driver" control (cua-driver stop)
for the runaway-`serve` case.
